setup MTU in Movian RPI or startup script.

When I was using movian on PS3 there was no problem with MTU because PS3 allowed to setup it in network configuration.

Movian is using connman which does not allow to setup MTU and EVEN WORSE!This connection manager does not take MTU from DHCP.My DHCP manages MTU on my network and standard Linux machines take this setting from DHCP.

Also I added a sleep in the script when testing it because the splash screen will show "Running boot script" while executing the script, and if the script is too quick the text will just flicker by. Maybe the sleep is needed also depending on how fast connman sets up the interface. I'm not sure TBH, but this should get you started.

To run something on boot is really useful thing not only to setup networking interfaces but usually for the most workarounds.For example on KODI I setup timeservers when there was a bug in it.Timerserver is also a very big issue because RPI does not have RTC.

Now I quit from KODI after found Movian for RPI but there is still some cool things to get from KODI to implement on Movian.For Example setting up Display during Playback via XML templates:Each template consists of what to show and where in different modes like in Movian: Standard, Enter, F2, F4, F6I configured there in "Standard mode" to show clock() in the upper right corner always because my wife required it.Hope one day it will arrive to Movian...